If there's one over-used buzzword currently making the rounds in the technology industry, it's 'post-PC world' - or the notion that desktops and laptops are a dying breed. Todd Bradley, executive vice president of HP's printing and personal systems group, thinks this is a nonsensical notion - and he's right.

I think you are missing the basic use cases. That's what really matters. If a tablet can ultimately fill in for the use cases of a traditional PC, then ultimately it will supplant the PC. And I am certain they can. It's really just a matter of time before the software is all in place, and not much time at that. Then all the hardware vendors have to do is make it easy to walk up to a *terminal* and tap into the tablet.

A terminal can be any supplemental interface, but in the PC case obviously it is keyboard and mouse, and optionally a larger monitor.

If a tablet can ultimately fill in for the use cases of a traditional PC, then ultimately it will supplant the PC. And I am certain they can.

Tablets have some overlap with tasks a PC currently performs, but are unlikely to replace a PC entirely for quite some time, if ever.
Right now I'm using three monitors. The two guys next to me use six monitors each. Monitoring alarms, Visio-style design sheets and managing multiple disparate systems. I'm sure there are plenty of other (better) use cases, too.
Your world may make do with a display and input device, but many other people need more.

I think you are missing the basic use cases. That's what really matters. If a tablet can ultimately fill in for the use cases of a traditional PC, then ultimately it will supplant the PC.

By saying, a tablet can ultimately fill in for the use cases of a traditional PC.

Then these are the traditional cases of a Traditional Personal Computer(tm):

Please answer,

In the future:

I can do multi-OS installations on a tablet?

I can upgrade any component on a tablet(MOBO/CPU/GPU/HDD)?

I can wipe out the OS on a tablet if it gets corrupted and then install all my PREVIOUS software on it?

I can run high-end software on it? Think about Blender, Maya, Lightwave, Modo, CorelDraw, Illustrator, Photoshop as these software needs multi-core CPU and GPU power??? Not to mention those custom software developed by companies for in-house use!

Yeah, tablets are now quad-core, and they can be stacked together in "hundreds or thousands" to form a cluster / HPC, so that we can render images generated by our 3D software in minutes? Then, how much it will cost in the future? Will it cost less than buying off-the-shelf components?

Yes, in the future they will have more cores, but do you believe that in the PC industry, it won't advance further into more powerful CPUs with more powerful GPUs?

You mean, I can run high-end games on a tablet in the future? So if it can run today's high-end, what do you expect from the PC gaming industry? Just watching movies?

But then, the PC components(CPU/GPU/MOBO/HDD/Mem) will morph into smaller form factors, so that in the future, it is possible to stack them together to form a tablet, including a multi-touch monitor and then I can create a PC out from it. What will happen to the tablets at that time then?

I can go on and on, with so many use cases of a traditional PC that are not possible in a tablet, now and in the future.

Sure, the Tablet supplants the PC's use cases of checking email, opening doc attachments, viewing/reading books. Editing documents, playing casual games, viewing video clips. But that's it, a tablet is a supplement to the Traditional PC, a helper.